[infra] Assembles the SDK using GN rather than create_sdk.py

build/toolchain/win/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 declare_args() {
   # Path to the directory containing the VC binaries for the right
   # combination of host and target architectures. Currently only the
   # 64-bit host toolchain is supported, with either 32-bit or 64-bit targets.
   # If vc_bin_dir is not specified on the command line (and it normally
   # isn't), we will dynamically determine the right value to use at runtime.
@@ skipping 147 matching lines @@
       ]
       link_output = libname
       depend_output = libname
 
       # The use of inputs_newline is to work around a fixed per-line buffer
       # size in the linker.
       rspfile_content = "{{libs}} {{solibs}} {{inputs_newline}} {{ldflags}}"
     }
 
     tool("link") {
-      rspfile = "{{output}}.rsp"
+      binary_output =
+          "{{root_out_dir}}/{{target_output_name}}{{output_extension}}"
+      rspfile = "$binary_output.rsp"
 
-      link_command = "$python_path gyp-win-tool link-wrapper $env False link.exe /nologo /OUT:{{output}} /PDB:{{output}}.pdb @$rspfile"
+      link_command = "$python_path gyp-win-tool link-wrapper $env False link.exe /nologo /OUT:$binary_output /PDB:$binary_output.pdb @$rspfile"
 
       # TODO(brettw) support manifests
       #manifest_command = "$python_path gyp-win-tool manifest-wrapper $env mt.exe -nologo -manifest $manifests -out:{{output}}.manifest"
       #command = "cmd /c $link_command && $manifest_command"
       command = link_command
 
       default_output_extension = ".exe"
-      description = "LINK {{output}}"
+      description = "LINK $binary_output"
       outputs = [
-        "{{root_out_dir}}/{{target_output_name}}{{output_extension}}",
+        binary_output,
+        "{{root_out_dir}}/{{target_output_name}}.lib",
       ]
 
       # The use of inputs_newline is to work around a fixed per-line buffer
       # size in the linker.
       rspfile_content = "{{inputs_newline}} {{libs}} {{solibs}} {{ldflags}}"
     }
 
     tool("stamp") {
       command = "$python_path gyp-win-tool stamp {{output}}"
       description = "STAMP {{output}}"
@@ skipping 46 matching lines @@
   }
   msvc_toolchain("clang_x64") {
     environment = "environment.x64"
     current_cpu = "x64"
     prefix = rebase_path("//third_party/llvm-build/Release+Asserts/bin",
                          root_build_dir)
     cl = "${goma_prefix}$prefix/clang-cl.exe"
     is_clang = true
   }
 }